title: Evaluation of the bitter-masking potential of food proteins for EGCG by a cell-based human bitter taste receptor assay and binding studies.
abstract: Epigallocatechin gallate (EGCG) has been ascribed to several health benefits, but its bitter taste influences the liking of products with high concentrations of this compound. β-Casein, in particular, and several gelatins are known as strong binders of EGCG, contrary to β-lactoglobulin. The current study aimed at relating the EGCG-binding characteristics of those proteins and their food-grade equivalents to their effects on reducing bitter receptor activation by EGCG in vitro and their bitter-masking potential in vivo. Also in the bitter receptor assay, β-casein showed the strongest effect, with a maximum reduction of hTAS2R39 activation of about 93%. A similar potency was observed for Na-caseinate. β-Lactoglobulin had little effect on bitter receptor activation, as expected based on its low binding affinity for EGCG. The bitter-masking potential of Na-caseinate was confirmed in vivo using a trained sensory panel. β-Lactoglobulin also slightly reduced EGCG bitter perception, which could not be directly related to its binding capacity. The bitter receptor assay appeared to be a valid tool to evaluate in vitro the efficacy of food proteins as complexing agents for masking bitterness.
authors.affiliation: Laboratory of Food Chemistry, Wageningen University , Bornse Weilanden 9, 6708, Wageningen, The Netherlands.
authors.forename: Maxime C
authors.initials: MC
authors.lastname: Bohin
authors.forename: Wibke S U
authors.initials: WS
authors.lastname: Roland
authors.forename: Harry
authors.initials: H
authors.lastname: Gruppen
authors.forename: Robin J
authors.initials: RJ
authors.lastname: Gouka
authors.forename: Harry T W M
authors.initials: HT
authors.lastname: van der Hijden
authors.forename: Peter
authors.initials: P
authors.lastname: Dekker
authors.forename: Gerrit
authors.initials: G
authors.lastname: Smit
authors.forename: Jean-Paul
authors.initials: JP
authors.lastname: Vincken
mesh_terms: D002364:Caseins / Q000737:chemistry / Q000378:metabolism*; D002392:Catechin / Q000031:analogs & derivatives* / Q000737:chemistry / Q000378:metabolism; D005260:Female; D006801:Humans; D007700:Kinetics; D008297:Male; D011485:Protein Binding; D011956:Receptors, Cell Surface / Q000737:chemistry / Q000378:metabolism*; D013649:Taste
chemical_list: D002364:Caseins; D011956:Receptors, Cell Surface; C557300:TAS2R39 protein, human; D002392:Catechin; C045651:epigallocatechin gallate